CN107655504B - Method for filtering pulse interference in optical fiber demodulation system based on self-adaptive threshold - Google Patents
Method for filtering pulse interference in optical fiber demodulation system based on self-adaptive threshold Download PDFInfo
- Publication number
- CN107655504B CN107655504B CN201710756970.8A CN201710756970A CN107655504B CN 107655504 B CN107655504 B CN 107655504B CN 201710756970 A CN201710756970 A CN 201710756970A CN 107655504 B CN107655504 B CN 107655504B
- Authority
- CN
- China
- Prior art keywords
- filtering
- peak
- optical fiber
- demodulation
- fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 56
- 238000001914 filtration Methods 0.000 title claims abstract description 51
- 239000013307 optical fiber Substances 0.000 title claims abstract description 42
- 239000000835 fiber Substances 0.000 claims abstract description 48
- 238000001228 spectrum Methods 0.000 claims abstract description 19
- 238000006243 chemical reaction Methods 0.000 claims abstract description 14
- 230000000694 effects Effects 0.000 claims abstract description 9
- 230000003287 optical effect Effects 0.000 claims description 13
- 230000003044 adaptive effect Effects 0.000 claims description 7
- 239000011521 glass Substances 0.000 claims description 4
- 238000001514 detection method Methods 0.000 claims description 3
- 238000011161 development Methods 0.000 claims description 3
- 238000009499 grossing Methods 0.000 claims description 3
- 238000005070 sampling Methods 0.000 claims description 3
- 238000012360 testing method Methods 0.000 claims description 3
- 238000012795 verification Methods 0.000 claims description 3
- 238000002310 reflectometry Methods 0.000 claims description 2
- 238000000411 transmission spectrum Methods 0.000 claims description 2
- 238000012544 monitoring process Methods 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000000985 reflectance spectrum Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
- G01D5/35309—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer
- G01D5/35312—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer using a Fabry Perot
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optical Communication System (AREA)
- Optical Transform (AREA)
Abstract
The invention provides a method for filtering pulse interference in an optical fiber demodulation system based on a self-adaptive threshold, which comprises the following steps: firstly, a fiber grating sensor demodulation system is built based on a fiber Fabry-Perot tunable filter demodulation method, and analog-digital conversion is carried out on a central wavelength reflection spectrum signal after photoelectric conversion; secondly, the first-order lag filtering is adopted to smoothly acquire the digital signals, so that the waveforms of the signals are smoother; thirdly, pulse interference is filtered out through amplitude limiting filtering based on a self-adaptive threshold value, so that the demodulation precision is improved; fourthly, demodulating the fiber bragg grating sensor by using the filtered result, and comparing and verifying the filtering effect; through the steps, the method for filtering the pulse interference in the optical fiber demodulation system based on the self-adaptive threshold is realized, the pulse interference in the optical fiber demodulation system can be efficiently and accurately filtered, the problem of low precision of the optical fiber demodulation system in the actual use process is solved, and the method is convenient to apply to actual engineering.
Description
Technical Field
The invention provides a method for filtering pulse interference in an optical fiber demodulation system based on an adaptive threshold, namely a method for filtering pulse interference in an optical fiber demodulation system based on an adaptive threshold, which can efficiently and accurately filter pulse interference in the optical fiber demodulation system by setting a double threshold which changes according to actual data, and aims to improve the precision of the optical fiber demodulation system so as to meet the requirement of structural health monitoring in practical application. In addition, the method is beneficial to popularization and application of the optical fiber sensor in the field of practical engineering, and belongs to the technical field of structural health monitoring.
Background
The optical fiber sensor can monitor the stress strain of the local area of the cloth patch in real time, has the advantages of electromagnetic interference resistance, corrosion resistance, high sensitivity, intrinsic passivity, easiness in maintenance, light weight, corrosion resistance and the like, and is widely applied to various large electromechanical, petrochemical and strong electromagnetic interference environments, inflammability, explosiveness and strong corrosion environments.
Common filtering methods include weighted average filtering, sliding average filtering and the like, so as to achieve the purposes of flattening the waveform and filtering out high-frequency small signals. But the interference to the pulse signal existing in the digital signal cannot be filtered effectively and can affect the sensitivity of the waveform. On the other hand, in digital filtering, an anti-pulse interference average filtering method is mostly adopted for pulse interference, but when the method is used for filtering of a fiber grating demodulation digital signal, certain influence is caused on a fiber grating reflection spectrum signal.
Based on the current situation and the problems, the method for filtering the pulse interference in the optical fiber demodulation system based on the self-adaptive threshold can efficiently and accurately filter the pulse interference in the optical fiber demodulation system by setting the double thresholds which change according to actual data, and aims to improve the precision of the optical fiber demodulation system so as to meet the requirement of structure health monitoring in practical application.
Disclosure of Invention
The invention has the following objects:
the method for filtering the pulse interference in the optical fiber demodulation system based on the self-adaptive threshold can efficiently and accurately filter the pulse interference in the optical fiber demodulation system by setting the double thresholds which change according to actual data, aims to improve the precision of the optical fiber demodulation system, is beneficial to popularization and application of an optical fiber grating sensor in the field of actual engineering, and is convenient for health monitoring of a structure.
The specific technical scheme is as follows:
the invention relates to a method for filtering pulse interference in an optical fiber demodulation system based on a self-adaptive threshold, which comprises the following specific steps:
step one, a fiber grating sensor demodulation system is built based on a fiber Fabry-Perot tunable filter demodulation method, and Analog to digital conversion (ADC) is carried out on a center wavelength reflection spectrum signal after photoelectric conversion;
step two, the digital signals acquired smoothly are filtered by first-order lag, so that the waveforms of the signals are smoother;
step three, amplitude limiting filtering based on self-adaptive threshold value filters pulse interference, and therefore demodulation precision is improved
Demodulating the fiber bragg grating sensor by using the filtered result, and comparing and verifying the filtering effect;
the optical fiber Fabry-Perot tunable filter in the step one is a multi-beam filter composed of two parallel glass plates, wherein the opposite inner surfaces of the two glass plates have high reflectivity, and the characteristic is that when the frequency of incident light meets the resonance condition, the transmission spectrum of the incident light has a very high peak value, which corresponds to very high transmissivity; the demodulation method based on the fiber Fabry-Perot tunable filter is a method for demodulating an optical fiber on the basis of using the fiber Fabry-Perot tunable filter.
The method comprises the following steps that a fiber grating sensor demodulation system is built based on a fiber Fabry-Perot tunable filter demodulation method in the step one, and analog-to-digital conversion (ADC) is carried out on a center wavelength reflection spectrum signal after photoelectric conversion; the method comprises the following steps: selecting an optical fiber sensor with the model of EDF-MP980, adopting an optical fiber Fabry-Perot tunable filter demodulation method, enabling light of a broadband light source to pass through an F-P cavity, dividing the light into two paths of light after passing through an optical coupler, enabling the first path of light to enter an optical fiber grating sensor, and enabling the other path of light to enter an optical comb filter. The reflected signal of the first path of light passes through the output of the optical coupler. The wavelength of the fiber grating reflected light can be obtained by measuring the transmitted light of the optical comb filter and the fiber grating reflected light and calculating, so that the demodulation of the fiber grating sensor is realized.
The first-order lag filtering in step two refers to calculating previous data and current data by using a function, so as to filter out an interference waveform.
Wherein, in the step two, the acquired digital signals are smoothed by adopting first-order lag filtering; the method comprises the following steps: smoothing the waveform using the following equation:
Y(t)＝(1-α)X(t)+αX(t-1)
where α is a first order lag filter coefficient; y (t) represents a filtering effect; x (t) represents a detected voltage digital signal; x (t-1) represents the last detection value.
Wherein the "adaptive threshold based clipping filter filters out impulse interference" described in step three; the method comprises the following steps: the self-adaptive threshold value filtering uses two threshold values which are respectively a width threshold value and a peak value judgment threshold value of a fiber grating reflection spectrum peak, the peak value judgment threshold value is (m) and is used for judging whether the peak exists, and the width threshold value of the fiber grating reflection spectrum peak is
To judge the authenticity of the peaks.
Wherein, in the step four, the fiber grating sensor is demodulated by using the filtered result, and the filtering effect is compared and verified; the method comprises the following steps: and (3) establishing a fiber grating demodulator light path and a circuit hardware platform for test verification. The FPGA board model used is XC7Z020-1CLG484I integrated development board Miz702 (Nanjing Mi Union electronics), and is matched with a high-speed AD acquisition chip with the model of AD9244 to carry out AD acquisition, and the sampling frequency is 5 MHz. Then, the fiber bragg grating sensor is demodulated, and the demodulation results before and after filtering are compared to verify the function of the method in filtering pulse interference in the fiber bragg grating demodulation system.
Through the steps, the method for filtering the pulse interference in the optical fiber demodulation system based on the self-adaptive threshold is realized, the pulse interference in the optical fiber demodulation system can be efficiently and accurately filtered, the problem of low precision of the optical fiber demodulation system in the actual use process is solved, and the method is convenient to apply to actual engineering.
(III) the invention has the advantages that:
the method for filtering the pulse interference in the optical fiber demodulation system based on the self-adaptive threshold can filter the pulse interference in the optical fiber demodulation system, so that the precision of the demodulation system is improved, the implementation mode is simple, no complex algorithm is adopted, and the applicability and operability are strong.
Drawings
FIG. 1 is a flow chart of the method of the present invention.
Fig. 2 is a schematic diagram of an optical switch cascade module.
Fig. 3 does not take the demodulation result obtained by filtering.
Fig. 4 shows the demodulation result obtained after the filtering method of the present invention.
The numbers, symbols and codes in the figures are explained as follows:
in fig. 2: "(m + 1)" is pm+1A threshold value of (d); "Y (t)" is the filtering effect; "p" ism"is the peak value of the fiber grating reflection spectrum; "τ (m)" is pmThe width of (d); "t" sm"is the time at which the peak begins; 't'm"is the time when the peak ends; "Tm"start time of broadening; 'T'm"is the termination time of the broadening.
Detailed Description
The invention discloses a method for filtering pulse interference in an optical fiber demodulation system based on an adaptive threshold, which comprises the following specific steps as shown in figure 1:
step one, building a fiber grating sensor demodulation system based on a fiber Fabry-Perot tunable filter demodulation method and performing Analog-to-digital conversion (ADC) on a center wavelength reflection spectrum signal subjected to photoelectric conversion
Selecting an optical fiber sensor with the model of EDF-MP980, adopting an optical fiber Fabry-Perot tunable filter demodulation method, enabling light of a broadband light source to pass through an F-P cavity, dividing the light into two paths of light after passing through an optical coupler, enabling the first path of light to enter an optical fiber grating sensor, and enabling the other path of light to enter an optical comb filter. The reflected signal of the first path of light passes through the output of the optical coupler. The wavelength of the fiber grating reflected light can be obtained by measuring the transmitted light of the optical comb filter and the fiber grating reflected light and calculating, so that the demodulation of the fiber grating sensor is realized. And (3) establishing a demodulation system by using the method, and performing analog-digital conversion on the central wavelength reflection spectrum signal subjected to photoelectric conversion to obtain a digital signal of a reflection spectrum.
Step two, the first-order lag filter smoothes the reflection spectrum digital signal by suppressing random noise and impulse noise in the original signal, and can be realized by the following formula: y (t) ═ (1- α) X (t) + α X (t-1)
Where α is a first order lag filter coefficient; y (t) represents a filtering effect; x (t) represents a detected voltage digital signal; x (t-1) represents the last detection value.
Step three, the self-adaptive threshold filtering uses two thresholds which are respectively a width threshold of a fiber grating reflection spectrum peak and a peak judgment threshold, the peak judgment threshold is (m) and is used for judging whether the peak exists, and the width threshold of the fiber grating reflection spectrum peak is
To judge the authenticity of the peaks. Let p be1，p2，…，pm，…，pn(n∈N*) Is the peak of the fiber grating reflection spectrum, in pmCalculate p as an examplem+1As shown in fig. 2;
if the first order lag filter has a value greater than (m) then a peak is present and the peak width is less than
Is a pulse signal. That is, only when there is a first order lagThe value of the filter is greater than (m) and the peak width ratio
The large peak may be taken as the true peak of the reflectance spectrum.
(m) is defined as follows:
wherein (m +1) is pm+1Threshold of (d), result of a first order lag in Y (t), tmIs the moment when the peak begins; t'mIs the moment when the peak ends.
When Y (t) ≧ m +1, p is indicatedm+1Is detected but is unable to judge its authenticity,
the peak used to find the true peak is defined by the following equation:
wherein
Is pm+1Is τ (m) is pmIs a safety margin, γ ∈ (0, 1).
When in use
The peak is considered to be true, otherwise it will be considered to be an impulse disturbance.
And step four, establishing a fiber grating demodulator light path and a circuit hardware platform for test verification. The FPGA board model used is XC7Z020-1CLG484I integrated development board Miz702 (Nanjing Mi Union electronics), and is matched with a high-speed AD acquisition chip with the model of AD9244 to carry out AD acquisition, and the sampling frequency is 5 MHz. The digital signals before and after filtering are respectively used for demodulating the fiber bragg grating, and demodulation results obtained without filtering are shown in fig. 3, and the results are obviously influenced by pulse interference; on the contrary, the demodulation result obtained by adopting the filtering method of the invention is shown in fig. 4, and the precision of the result is obviously improved, which shows that the method of the invention has good filtering function on the pulse interference in the fiber grating sensor demodulation system.
Claims (3)
1. A method for filtering impulse interference in an optical fiber demodulation system based on an adaptive threshold is characterized in that: the method comprises the following specific steps:
firstly, a fiber grating sensor demodulation system is built based on a fiber Fabry-Perot tunable filter demodulation method, and analog-to-digital conversion (ADC) is carried out on a center wavelength reflection spectrum signal after photoelectric conversion;
step two, the digital signals acquired smoothly are filtered by first-order lag, so that the waveforms of the signals are smoother;
step three, filtering out pulse interference based on amplitude limiting filtering of a self-adaptive threshold value, thereby improving the demodulation precision;
demodulating the fiber bragg grating sensor by using the filtered result, and comparing and verifying the filtering effect;
the optical fiber Fabry-Perot tunable filter in the step one refers to a multi-beam filter composed of two parallel glass plates, wherein the opposite inner surfaces of the two glass plates have high reflectivity, and the characteristic is that when the frequency of incident light meets the resonance condition, the transmission spectrum of the incident light has a very high peak value, which corresponds to very high transmissivity; the demodulation method based on the optical fiber Fabry-Perot tunable filter is a method for demodulating an optical fiber on the basis of using the optical fiber Fabry-Perot tunable filter;
the method comprises the steps that in the step one, a fiber grating sensor demodulation system is built based on a fiber Fabry-Perot tunable filter demodulation method, and analog-to-digital conversion (ADC) is carried out on a center wavelength reflection spectrum signal after photoelectric conversion; the method comprises the following steps: selecting an optical fiber grating sensor with the model of EDF-MP980, adopting an optical fiber Fabry-Perot tunable filter demodulation method, enabling light of a broadband light source to pass through an F-P cavity, dividing the light into two paths of light after passing through an optical coupler, enabling the first path of light to enter the optical fiber grating sensor, and enabling the other path of light to enter an optical comb filter; the reflected signal of the first path of light is output through the optical coupler; the wavelength of the fiber grating reflected light is obtained by measuring the transmitted light of the optical comb filter and the fiber grating reflected light and calculating, so that the demodulation of the fiber grating sensor is realized;
the step two is described as 'smoothing the acquired digital signal by adopting first-order lag filtering'; the method comprises the following steps: smoothing the waveform using the following equation:
Y(t)＝(1-α)X(t)+αX(t-1)
where α is a first order lag filter coefficient; y (t) represents a filtering effect; x (t) represents a detected voltage digital signal; x (t-1) represents the last detection value;
the adaptive threshold based clipping filter described in step three filters out impulse interference; the method comprises the following steps: the self-adaptive threshold filtering uses two thresholds, namely a width threshold of a fiber grating reflection spectrum peak and a peak judgment threshold, wherein the peak judgment threshold is (m) and is used for judging whether the peak exists, and the width threshold of the fiber grating reflection spectrum peak is phi (m) and is used for judging the authenticity of the peak; let p be1，p2，…，pm，…，pnIs the peak value of the fiber grating reflection spectrum, N belongs to N*Calculating pm+1An adaptive threshold of (a); if the first order lag filter has a value greater than (m) then a peak is present and the peak width is less than phi (m) is the pulse signal; that is, a true peak is only detected if the first order lag filter has a value greater than (m) and the peak width is greater than φ (m);
(m) is defined as follows:
wherein (m +1) is pm+1Is the result of a first order lag, tmIs the moment when the peak begins; t'mIs the time at which the peak ends;
when Y (t) ≧ m +1, p is indicatedm+1Detected but not judged as authentic,. phi. (m) is defined by the following equation to find the true peak:
wherein phi (m +1) is pm+1Is τ (m) is pmγ is a safety margin, γ ∈ (0, 1); "Tm"start time of broadening; 'T'm"is the termination time of the broadening; when τ (m +1) ≧ φ (m +1), the peak is considered true, otherwise it will be considered an impulse disturbance.
2. The method of claim 1, wherein the method comprises the steps of: the first-order lag filtering in the second step means that the previous data and the current data are calculated by using a function, so that the interference waveform is filtered.
3. The method of claim 1, wherein the method comprises the steps of: the fourth step of demodulating the fiber bragg grating sensor by using the filtered result and comparing and verifying the filtering effect; the method comprises the following steps: establishing a fiber grating demodulator light path and a circuit hardware platform for test verification; the FPGA board used is an integrated development board Miz702 with the model of XC7Z020-1CLG484I, and is matched with a high-speed AD acquisition chip with the model of AD9244 to carry out AD acquisition, and the sampling frequency is 5 MHz; then, the fiber bragg grating sensor is demodulated, and the demodulation results before and after filtering are compared to verify the function of the method in filtering pulse interference in the fiber bragg grating sensor demodulation system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710756970.8A CN107655504B (en) | 2017-08-29 | 2017-08-29 | Method for filtering pulse interference in optical fiber demodulation system based on self-adaptive threshold |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710756970.8A CN107655504B (en) | 2017-08-29 | 2017-08-29 | Method for filtering pulse interference in optical fiber demodulation system based on self-adaptive threshold |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107655504A CN107655504A (en) | 2018-02-02 |
| CN107655504B true CN107655504B (en) | 2020-10-27 |
Family
ID=61128749
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710756970.8A Active CN107655504B (en) | 2017-08-29 | 2017-08-29 | Method for filtering pulse interference in optical fiber demodulation system based on self-adaptive threshold |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107655504B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112353385B (en) * | 2020-10-21 | 2023-09-15 | 南京伟思医疗科技股份有限公司 | Training mode identification system, method and application based on variant sigmoid function classifier |
| CN112260696A (en) * | 2020-11-11 | 2021-01-22 | 天津津航计算技术研究所 | System for improving avionic pulse signal acquisition compression ratio based on FPGA |
| CN113155165B (en) | 2021-05-14 | 2022-07-05 | 武汉理工大学 | Interference type demodulation system and method for large-capacity fiber grating sensor network |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102879022A (en) * | 2012-09-25 | 2013-01-16 | 杭州联光电子有限公司 | Method and device for demodulating fiber bragg grating (FBG) sensor |
| CN104215605A (en) * | 2014-02-12 | 2014-12-17 | 中科融通物联科技无锡有限公司 | Method for fast dynamic-calibration of fiber bragg grating (FBG) demodulation system |
| CN104391417A (en) * | 2014-12-04 | 2015-03-04 | 武汉理工大学 | High-speed fiber grating demodulating system based on parallel scanning of tunable optical filters |
| CN106352905A (en) * | 2015-07-14 | 2017-01-25 | 中国电力科学研究院 | Fiber bragg grating demodulating system and demodulator |
| CN106706011A (en) * | 2016-12-27 | 2017-05-24 | 北京航空航天大学 | Method for filtering out pulse noise wave in demodulation of fiber Bragg grating sensor |
-
2017
- 2017-08-29 CN CN201710756970.8A patent/CN107655504B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102879022A (en) * | 2012-09-25 | 2013-01-16 | 杭州联光电子有限公司 | Method and device for demodulating fiber bragg grating (FBG) sensor |
| CN104215605A (en) * | 2014-02-12 | 2014-12-17 | 中科融通物联科技无锡有限公司 | Method for fast dynamic-calibration of fiber bragg grating (FBG) demodulation system |
| CN104391417A (en) * | 2014-12-04 | 2015-03-04 | 武汉理工大学 | High-speed fiber grating demodulating system based on parallel scanning of tunable optical filters |
| CN106352905A (en) * | 2015-07-14 | 2017-01-25 | 中国电力科学研究院 | Fiber bragg grating demodulating system and demodulator |
| CN106706011A (en) * | 2016-12-27 | 2017-05-24 | 北京航空航天大学 | Method for filtering out pulse noise wave in demodulation of fiber Bragg grating sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107655504A (en) | 2018-02-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107655504B (en) | Method for filtering pulse interference in optical fiber demodulation system based on self-adaptive threshold | |
| CN107402082B (en) | Brillouin scattering signal processing method and distributed optical fiber sensing system thereof | |
| CN101291055B (en) | Method for precisely marking arriving time of initial wave of fault generated traveling waves for electricity transmission line | |
| CN108955734B (en) | Cavity length demodulation method of optical fiber F-P temperature/pressure composite sensor | |
| CN112985639B (en) | Distributed optical fiber sensing method based on chirp removal and time domain sub-chirp pulse extraction | |
| CN110967599A (en) | Electric energy quality disturbance detection and positioning algorithm | |
| CN111273336B (en) | Gaussian forming method for digital nuclear pulse signal | |
| KR100780470B1 (en) | Adaptive target signal discrimination of surveillance radar | |
| CN108225385A (en) | A kind of overlapping FBG transducing signal peak value localization methods | |
| WO2016050547A1 (en) | Method of analysing a cable, based on an auto-adaptive correlation, for the detection of non-straightforward defects | |
| US20110191047A1 (en) | Wavelet Denoising for Time-Domain Network Analysis | |
| EP3304107A1 (en) | Reflectometry method and device for diagnosing cables in use | |
| Yang et al. | Partial discharge signal extraction method based on EDSSV and low rank RBF neural network | |
| CN105843779B (en) | A kind of real-time de-noising method towards POTDR backscattering optical signal | |
| CN112129535A (en) | Scraper conveyor bearing fault monitoring system based on fiber bragg grating sensing | |
| CN108809438A (en) | A kind of time difference compensation method and apparatus | |
| CN110635824B (en) | PLC channel impulse noise detection method and system using classification regression tree | |
| CN114444548A (en) | Wavelet sound denoising method and system based on robustness principal component analysis | |
| CN113726318A (en) | WM-based partial discharge white noise self-adaptive suppression method | |
| RU2395158C1 (en) | Digital signal filtration method | |
| CN111864688B (en) | Ultra-high voltage direct current control protection system OTDR (optical time Domain reflectometer) layered multi-stage event accurate extraction and positioning method | |
| CN103281472B (en) | Detection device for faxing ANSam signal and detection method thereof | |
| CN109039438A (en) | A kind of optical fiber link detection system and method based on digital chirp signal | |
| CN108802708B (en) | Single photon counting heterodyne detection method based on sequence reconstruction | |
| CN114543971B (en) | FP interference type sound wave detector and sound wave detection method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |